264 THE DIVING DUCKS 



THE DIVING DUCKS 

 [F. C. R JOURDAIN] 



In the following chapter the term " Diving Ducks " must be 

 understood as not including the group of " Sawbills," which of course, 

 in the literal sense of the words, are also diving ducks, but is confined 

 to the ducks of the genera Nyroca, Clangula, Harelda, Somateria, and 

 Oidemia. Of these, the three species of the genus Nyroca and one of 

 the genus Clangula are sufficiently numerous to be treated of below, 

 namely, the pochard, N. ferina (L.), the tufted-duck, N. fuligula (L.), 

 the scaup, N. marila (L.), and the goldeneye, C, clangula (L.), the 

 others being relegated to the "Rare Bird" section. One member 

 of the genus Harelda, the longtailed-duck, H. hyemalis (L.), is also 

 included, and a single representative of the genus Somateria, the 

 common-eider, S. mollissima (L.) ; while the genus Oidemia is repre- 

 sented by two species, the common-scoter, 0. nigra (L.), and the 

 velvet-scoter, 0. fusca (L.). 



All these ducks have certain points in common which distinguish 

 them from the surface-feeders. Instead of habitually seeking their 

 food either on the surface or in shallow water, after the ungainly 

 fashion with which we are familiar in the case of the tame duck, the 

 head and fore part of the body only being submerged, and the after 

 part sticking perpendicularly out of the water, the diving ducks prefer 

 to feed in deep water, with the body entirely submerged, and are 

 capable of remaining under water for considerable periods. 1 Struc- 

 turally they all have certain characteristics in common ; for instance, 

 in the diving ducks the hind-toe is always deeply lobed, while in the 

 surface-feeders the lobe is either absent or extremely narrow. Their 



1 It must not be inferred from this that the surface-feeders are incapable of diving ; for 

 instance, the shoveler can and does remain completely submerged for considerable periods 

 at a time. 



